Intensity-modulated light pattern for active stereo

ABSTRACT

The subject disclosure is directed towards projecting light in a pattern in which the pattern contains components (e.g., spots) having different intensities. The pattern may be based upon a grid of initial points associated with first intensities and points between the initial points with second intensities, and so on. The pattern may be rotated relative to cameras that capture the pattern, with captured images used active depth sensing based upon stereo matching of dots in stereo images.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation and claims priority to U.S.non-provisional patent application Ser. No. 13/915,626, filed Jun. 11,2013, which claims priority to provisional patent application Ser. No.61/812,232, filed Apr. 15, 2013.

BACKGROUND

In active depth sensing, such as used by active stereo systems, aprojector projects patterns of light such as infrared (IR) dots or linesto illuminate a scene being sensed. The projected patterns are thencaptured by a camera/sensor (two or more in stereo systems), with theimage (or images) processed to compute a depth map or the like.

For example, in stereo systems, stereo cameras capture two images fromdifferent viewpoints. Then, for example, one way to perform depthestimation with a stereo pair of images is to find correspondences oflocal patches between the images, e.g., to correlate each projected andsensed local dot pattern in the left image with a counterpart local dotpattern in the right image. Once matched, the projected patterns withinthe images may be correlated with one another, and disparities betweenone or more features of the correlated dots used to estimate (e.g.,triangulate) a depth to that particular dot pair.

IR lasers have been used to produce such patterns. In order to allow thestereo system to work over a wide range of depths, more powerful lasers(around 1W or more) are needed. At such power levels, multi-mode lasersare more cost-effective. However, using multi-mode lasers results in thedesign pattern looking blurrier at closer distances. This is problematicin active stereo depth sensing, because correlating the correct pairs ofleft and right pairs of dots is subject to more errors when the dots areblurred.

SUMMARY

This Summary is provided to introduce a selection of representativeconcepts in a simplified form that are further described below in theDetailed Description. This Summary is not intended to identify keyfeatures or essential features of the claimed subject matter, nor is itintended to be used in any way that would limit the scope of the claimedsubject matter.

Briefly, one or more of various aspects of the subject matter describedherein are directed towards an intensity-modulated light pattern foractive sensing. A projector including a laser and a diffractive opticalcomponent projects a light pattern towards a scene. The diffractiveoptical component is configured to output the light pattern as aplurality of sets of sub-patterns, with each set corresponding to adifferent range of intensities.

One or more aspects are directed towards generating a grid comprising afirst set of points, associating each point in the first set with anintensity value that is within a first intensity range, adding a secondset of points between subsets of points of the first set of points andassociating each point in the second set with an intensity value that iswithin a second intensity range. This subdivision process may berepeated if necessary. A diffractive optical component may be encodedbased upon the first set of points and the second set of points. Anothervariant is to generate a random set of points with approximately uniformdensity throughout, with a random subset of them having a specifiedrange of intensities, and the rest having a different range ofintensities.

One or more aspects are directed towards projecting light through adiffractive optical component to project a pattern comprising a firstset of spots corresponding to a first intensity range, and a second setof spots corresponding to a second intensity range. The positions of thespots in the first set are based upon an initial grid layout, and thepositions of spots in the second set of spots are based upon thepositions of the first set of spots. The first set of spots and thesecond set of spots are sensed as left and right stereo camera images.The images are processed to correlate spots in the left image with spotsin the right image, in which scanlines of the images are not alignedwith the initial grid layout.

Other advantages may become apparent from the following detaileddescription when taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limitedin the accompanying figures in which like reference numerals indicatesimilar elements and in which:

FIG. 1 is a block diagram representing example components that may beused to project and capture a light pattern modulated with differentintensities, according to one or more example implementations.

FIG. 2 is a representation of an example of projecting dots havingdifferent intensities into a scene, according to one or more exampleimplementations.

FIGS. 3A and 3B are representations of a pattern may be designed basedupon a grid, and subdivision of points aligned via the grid, tofacilitate having points with different intensities, according to one ormore example implementations.

FIG. 4 is a representation of further subdivision of points havingdifferent intensities, according to one or more example implementations.

FIG. 5 is a flow diagram representing example steps in laying out pointsfor of different intensities, such as for encoding corresponding datainto a diffractive optical element, according to one or more exampleimplementations.

FIG. 6 is a block diagram representing example components of a devicethat projects a diffraction pattern of light having differentintensities, according to one example implementation.

FIGS. 7 and 8 are representations of how non-rotation versus rotation ofa projected pattern affects scanning of captured images that include theprojected pattern, according to one or more example implementations.

FIG. 9 is a representation of how dots of different intensities may becaptured in a part of an image, and moved over time, according to one ormore example implementations.

FIG. 10 is a block diagram representing an exemplary non-limitingcomputing system or operating environment, in the form of a gamingsystem, into which one or more aspects of various embodiments describedherein can be implemented.

DETAILED DESCRIPTION

Various aspects of the technology described herein are generallydirected towards having a light pattern projected into a scene, in whichthe light pattern is configured to provide for enhanced patternmatching, including at different depths to illuminated objects. In oneaspect, a light pattern includes intermixed points of light (e.g., spotssuch as dots) of different intensities. The technology also leveragesthe depth-dependent appearance of the pattern by having the patterninclude points that are semi-randomly distributed.

As will be understood, the peak intensities of neighboring points aredifferent. This results in local changes in intensity independent of thescene depth, to allow stereo matching to function properly.

It should be understood that any of the examples herein arenon-limiting. For example, the projected light pattern may use spots,generally exemplified herein as dots, but the dots may be of any shape.As another, the dots are exemplified as arranged according to atriangular grid, however this is only one example, and otherarrangements (e.g., a hexagonal grid) may be implemented. Rotationangles of the patterns (described below), different ranges or values ofintensity peaks (e.g., for large, medium and small intensities) fromthose described herein may be used, and so on. As such, the presentinvention is not limited to any particular embodiments, aspects,concepts, structures, functionalities or examples described herein.Rather, any of the embodiments, aspects, concepts, structures,functionalities or examples described herein are non-limiting, and thepresent invention may be used various ways that provide benefits andadvantages in active depth sensing and image processing in general.

FIG. 1 shows an example system in which stereo cameras 102 and 103 of animage capturing system or subsystem 104 capture images synchronized intime (e.g., the cameras are “genlocked”). In one implementation thecameras capture infrared (IR) images, as IR does not affect the visibleappearance of the scene (which is highly advantageous, such as in videoconferencing and object modeling applications). As can be readilyappreciated, in some scenarios such as studio environments, more thantwo IR depth-sensing cameras may be present. Further, one or more othercameras may be present in a given system, such as RBG cameras, and suchother cameras may be used to help correlate dot pairs in differentstereo images, for example.

In FIG. 1, a projector 106 is shown that projects an IR pattern onto ascene, such as a pattern of spots (e.g., dots) or a line pattern,although other spot shapes and/or pattern types may be used. Forpurposes of brevity, dots are generally described hereinafter. Byilluminating the scene with a relatively large number of distributedinfrared dots, the cameras 102 and 103 capture texture data as part ofthe infrared image data. As described herein, to facilitate moreaccurate dot matching between left and right images, the dots in thepattern are arranged with different intensities, and also the patternmay be rotated relative to the cameras. The pattern with intensitymodulation may be designed (e.g., encoded) into a diffractive opticalcomponent (a diffractive optical element or combination of elements)that disperse laser light into the scene, e.g., as a dot pattern.

FIG. 2 exemplifies this projection concept. The projector 106,represented as a circle in between the stereo cameras 102 and 103,projects a dot pattern onto a scene 222. The dot pattern is modulatedwith different intensities, and the dot pattern may be rotated (e.g.,fifteen degrees) relative to the cameras' orientation. The cameras 102and 103 capture the dots as they reflect off of object surfaces in thescene 222 and (possibly) the background. In general, one or morefeatures of the captured dots are indicative of the distance to thereflective surface. Note that FIG. 2 is not intended to be to scale, norconvey any sizes, distance, dot distribution pattern, dot density and soon. However, it is understood that different intensities exist in thedot pattern, and that the dot pattern may be rotated relative to thecameras.

Note that the placement of the projector 106 may be outside the cameras(e.g., FIG. 1), or in between the cameras (FIG. 2) or at anotherlocation, such as above or below one or both of the cameras. Theexamples herein are in no way limiting of where the cameras and/orprojector are located relative to one another, and similarly, thecameras may be positioned at different positions relative to each other.

In one implementation the example image capturing system or subsystem104 includes a controller 108 that via a camera interface 110 controlsthe operation of the cameras 102 and 103. The exemplified controller viaa projector interface 112 also controls the operation of the projector106. For example, the cameras 102 and 103 are synchronized (genlocked)to capture stereo images at the same time, such as by a controllersignal (or different signals for each camera). The projector 106 may beturned on or off, pulsed, and otherwise have one or more parameterscontrollably varied, for example.

The images 116 captured by the cameras 102 and 103 are provided to animage processing system or subsystem 118. In some implementations, theimage processing system 118 and image capturing system or subsystem 104,or parts thereof, may be combined into a single device. For example ahome entertainment device may include all of the components shown inFIG. 1 (as well as others not shown). In other implementations, parts(or all) of the image capturing system or subsystem 104, such as thecameras and projector, may be a separate device that couples to a gamingconsole, personal computer, mobile device, dedicated processing deviceand/or the like. Indeed, a gaming console is exemplified in FIG. 10 asone environment that may be used for processing images into depth data.

The image processing system or subsystem 118 includes a processor 120and a memory 122 containing one or more image processing algorithms 124.One or more depth maps 126 may be obtained via the algorithms 124 suchas by extracting matching features (such as dots and/or lines). Forexample, as is known, such as described in U.S. published patentapplication no. 20130100256, hereby incorporated by reference, differentdots or other projected elements have different features when captured,including intensity (brightness), depending on the distance from theprojector to the reflective surfaces and/or the distance from the camerato the reflective surfaces. As is also known, the dots in differentimages taken at the same time (e.g., with genlocked stereo cameras) maybe correlated with one another, such as by matching small (e.g., RGB)patches between RGB color images of the same scene captured at the sameinstant. Thus, with captured images, known algorithms can determineindividual depth-related features (depth maps) by matching projectedlight components (e.g., dots) in each image, using disparities ofcertain features between matched dots to determine depths. This is oneway in which a depth map may be obtained via stereo image processing.Also shown in FIG. 1 is an interface 132 to the image processing systemor subsystem 118, such as for connecting a keyboard, game controller,display, pointing device microphone for speech commands and/or the likeas appropriate for a user to interact with an application or the likethat uses the depth map.

FIGS. 3A and 3B, along with FIG. 4 show the concept of subdivision, inwhich dots of larger intensity (larger dots with an “X” shaped crosstherein) are arranged in a triangular grid layout 330 (FIG. 3A). In FIG.3B, each triangle of the larger intensity dots is subdivided bytriangles of lesser intensity dots (circles), providing the pattern 332.In FIG. 4, each of those sub-triangle sub-patterns is further subdividedby even lesser intensity dots (smaller-sized circles relative to thosein FIG. 3B). Thus, FIG. 4 represents a triangular pattern 440 of higherintensity dots, medium intensity dots, and lower intensity dots. The dotsizes relative to the distribution pattern and each other are onlyintended to illustrate distribution of dots of differing relativeintensities or intensity ranges, and are not intended to convey anyparticular intensity levels or ranges.

FIG. 5 summarizes subdivision, beginning at step 502 where in thisexample a triangular grid of a specified between-vertex distance isgenerated, e.g., comprising regular triangles or substantially regulartriangles (or other polygons). The intensity peaks are set to a highvalue; however rather than being the same intensity value for eachpoint, the high values may be randomly set to be within a high range(step 504), e.g., between 200-255 (with 255 being the maximumintensity). Note that as used herein, an intensity “range” includes arange with as little as one single fixed intensity value, e.g., a rangemay be from 200 to 200.

Step 506 represents adding points between the previously generatedpoints, e.g., as smaller sets of triangles (a “subdivision”) such asshown in FIG. 3B. Step 508 randomly sets the intensity peaks of thesepoints to be within a lower range, e.g., between 100-125. Note thatthese example intensity ranges do not overlap one another, but it isfeasible to have different ranges overlap to an extent; if weightedrandom techniques may be used to bias most values in overlapping rangesaway from one another.

Step 510 evaluates whether subdivision has been completed to the lowestdesired level, which is configurable. Thus, by returning to step 506,another subdivision of points may be optionally added, (such asexemplified in FIG. 4), with an even lower range of intensities, and soon, until the desired pattern and sets of intensities/intensity rangesis reached. The result is a projection pattern that containssub-patterns, in this example different sets of triangular sub-patterns,such as a larger intensity sub-pattern set and a smaller-intensitysub-pattern set (FIG. 3B), or small, medium and large intensitysub-pattern sets (FIG. 4) and so on. In general, the sets/sub-patternsare interleaved via subdivision.

Note that once the intensity-modulated pattern is designed, such as viathe example steps of FIG. 5, the diffractive optical element or elementsmay be manufactured in known ways to output that pattern. Various eyesafe diffractive optical element arrangements are described in theaforementioned provisional patent application Ser. No. 61/812,232.However, as another (optional) step, step 512 represents pseudo-randomlyrearranging (e.g., slightly “littering”) at least some of the pointsinto modified positions, such as to further reduce repetition intervals.Typically this repositioning of a point is small relative to itsrespective triangle (or other grid pattern), whereby the regular polygonor substantially regular polygon is now modified to be onlygenerally/approximately regular.

FIG. 6 is one such example configuration in which a diffractive opticalcomponent 660 (e.g., diffractive optical one or more elements) isconfigured to output an intensity-modulated illumination pattern. Thecomponent 660 may be built into or coupled to device 662, such as abuilt into or part of a home entertainment device. A laser 664 (e.g.,multimode) provides the light source. Stereo cameras 666A and 666Bcapture the reflection from an illuminated object (e.g., person 668) anduse the captured images as desired; note that a single camera may beused in a given implementation.

As represented n FIG. 6, the diffractive optical component 660 dispersesthe laser light into a large number of spots based upon the patterndesigned as described herein, such as on the order of 100,000 dots. Someof the pattern is represented in FIG. 1 by the solid lines coming fromthe element and by the dots on the object/person 668 and image plane670. Note that as with any of the figures herein, neither FIG. 6 nor itscomponents are intended to be to scale or convey any particulardistance, distribution and/or the like.

As represented in FIG. 6, the diffractive optical component 660disperses the laser light into a large number of spots based upon thepattern designed as described herein, such as on the order of 100,000dots. Some of the pattern is represented in FIG. 6 by the solid linescoming from the component 660 and by the dots on the object/person 668and image plane 670. Note that as with any of the figures herein,neither FIG. 6 nor its components are intended to be to scale or conveyany particular distance, distribution and/or the like. In FIG. 8,camera-captured dots of part of a rotated left pattern 880L are shownalongside parts of a rotated right pattern 880R. As can be seen, whenscanning a line of pixels to match dot A, for example, neither dot B nordot D will be encountered. In this way, the rotation (e.g., by fifteendegrees in this example, although other rotational angles may be used)helps to provide a larger repetition interval along the scanline(x-direction).

Rotation and intensity distribution is generally shown in the partialimage representation 990 of FIG. 9, where the dots are illustrated byconcentric circles, and (some relative) intensity by the sizes thereof.The pixels are represented by the square blocks behind the dots. Notethat in FIG. 9 the different diameters of the circles only suggestchanges in intensity; the size of the circles and the grid squares arenot intended to convey any particular scale, resolution, or the like,nor any particular intensity value or relative intensity values (otherthan within at least two different ranges). Further, the density of thedots and/or their sizes or distribution are not intended to representany actual density and/or distribution.

As can be seen, there is provided a light pattern modulated withdifferent intensities. The pattern may be based upon a grid, andprojected such that the cameras that capture the light pattern are notaligned with the grid on which the pattern was based. Theintensity-modulated pattern provides for more robust stereomatching/depth sensing.

Example Operating Environment

It can be readily appreciated that the above-described implementationand its alternatives may be implemented on any suitable computingdevice, including a gaming system, personal computer, tablet, DVR,set-top box, smartphone and/or the like. Combinations of such devicesare also feasible when multiple such devices are linked together. Forpurposes of description, a gaming (including media) system is describedas one exemplary operating environment hereinafter.

FIG. 10 is a functional block diagram of an example gaming and mediasystem 1000 and shows functional components in more detail. Console 1001has a central processing unit (CPU) 1002, and a memory controller 1003that facilitates processor access to various types of memory, includinga flash Read Only Memory (ROM) 1004, a Random Access Memory (RAM) 1006,a hard disk drive 1008, and portable media drive 1009. In oneimplementation, the CPU 1002 includes a level 1 cache 1010, and a level2 cache 1012 to temporarily store data and hence reduce the number ofmemory access cycles made to the hard drive, thereby improvingprocessing speed and throughput.

The CPU 1002, the memory controller 1003, and various memory devices areinterconnected via one or more buses (not shown). The details of the busthat is used in this implementation are not particularly relevant tounderstanding the subject matter of interest being discussed herein.However, it will be understood that such a bus may include one or moreof serial and parallel buses, a memory bus, a peripheral bus, and aprocessor or local bus, using any of a variety of bus architectures. Byway of example, such architectures can include an Industry StandardArchitecture (ISA) bus, a Micro Channel Architecture (MCA) bus, anEnhanced ISA (EISA) bus, a Video Electronics Standards Association(VESA) local bus, and a Peripheral Component Interconnects (PCI) busalso known as a Mezzanine bus.

In one implementation, the CPU 1002, the memory controller 1003, the ROM1004, and the RAM 1006 are integrated onto a common module 1014. In thisimplementation, the ROM 1004 is configured as a flash ROM that isconnected to the memory controller 1003 via a Peripheral ComponentInterconnect (PCI) bus or the like and a ROM bus or the like (neither ofwhich are shown). The RAM 1006 may be configured as multiple Double DataRate Synchronous Dynamic RAM (DDR SDRAM) modules that are independentlycontrolled by the memory controller 1003 via separate buses (not shown).The hard disk drive 1008 and the portable media drive 1009 are shownconnected to the memory controller 1003 via the PCI bus and an ATAttachment (ATA) bus 1016. However, in other implementations, dedicateddata bus structures of different types can also be applied in thealternative.

A three-dimensional graphics processing unit 1020 and a video encoder1022 form a video processing pipeline for high speed and high resolution(e.g., High Definition) graphics processing. Data are carried from thegraphics processing unit 1020 to the video encoder 1022 via a digitalvideo bus (not shown). An audio processing unit 1024 and an audio codec(coder/decoder) 1026 form a corresponding audio processing pipeline formulti-channel audio processing of various digital audio formats. Audiodata are carried between the audio processing unit 1024 and the audiocodec 1026 via a communication link (not shown). The video and audioprocessing pipelines output data to an AN (audio/video) port 1028 fortransmission to a television or other display/speakers. In theillustrated implementation, the video and audio processing components1020, 1022, 1024, 1026 and 1028 are mounted on the module 1014.

FIG. 10 shows the module 1014 including a USB host controller 1030 and anetwork interface (NW I/F) 1032, which may include wired and/or wirelesscomponents. The USB host controller 1030 is shown in communication withthe CPU 1002 and the memory controller 1003 via a bus (e.g., PCI bus)and serves as host for peripheral controllers 1034. The networkinterface 1032 provides access to a network (e.g., Internet, homenetwork, etc.) and may be any of a wide variety of various wire orwireless interface components including an Ethernet card or interfacemodule, a modem, a Bluetooth module, a cable modem, and the like.

In the example implementation depicted in FIG. 10, the console 1001includes a controller support subassembly 1040, for supporting four gamecontrollers 1041(1)-1041(4). The controller support subassembly 1040includes any hardware and software components needed to support wiredand/or wireless operation with an external control device, such as forexample, a media and game controller. A front panel I/O subassembly 1042supports the multiple functionalities of a power button 1043, an ejectbutton 1044, as well as any other buttons and any LEDs (light emittingdiodes) or other indicators exposed on the outer surface of the console1001. The subassemblies 1040 and 1042 are in communication with themodule 1014 via one or more cable assemblies 1046 or the like. In otherimplementations, the console 1001 can include additional controllersubassemblies. The illustrated implementation also shows an optical I/Ointerface 1048 that is configured to send and receive signals (e.g.,from a remote control 1049) that can be communicated to the module 1014.

FIG. 10 shows the module 1014 including a USB host controller 1030 and anetwork interface (NW I/F) 1032, which may include wired and/or wirelesscomponents. The USB host controller 1030 is shown in communication withthe CPU 1002 and the memory controller 1003 via a bus (e.g., PCI bus)and serves as host for peripheral controllers. The network interface1032 provides access to a network (e.g., Internet, home network, etc.)and may be any of a wide variety of various wire or wireless interfacecomponents including an Ethernet card or interface module, a modem, aBluetooth module, a cable modem, and the like. A system power supplymodule 1054 provides power to the components of the gaming system 1000.A fan 1056 cools the circuitry within the console 1001.

An application 1060 comprising machine instructions is typically storedon the hard disk drive 1008. When the console 1001 is powered on,various portions of the application 1060 are loaded into the RAM 1006,and/or the caches 1010 and 1012, for execution on the CPU 1002. Ingeneral, the application 1060 can include one or more program modulesfor performing various display functions, such as controlling dialogscreens for presentation on a display (e.g., high definition monitor),controlling transactions based on user inputs and controlling datatransmission and reception between the console 1001 and externallyconnected devices.

The gaming system 1000 may be operated as a standalone system byconnecting the system to high definition monitor, a television, a videoprojector, or other display device. In this standalone mode, the gamingsystem 1000 enables one or more players to play games, or enjoy digitalmedia, e.g., by watching movies, or listening to music. However, withthe integration of broadband connectivity made available through thenetwork interface 1032, gaming system 1000 may further be operated as aparticipating component in a larger network gaming community or system.

CONCLUSION

While the invention is susceptible to various modifications andalternative constructions, certain illustrated embodiments thereof areshown in the drawings and have been described above in detail. It shouldbe understood, however, that there is no intention to limit theinvention to the specific forms disclosed, but on the contrary, theintention is to cover all modifications, alternative constructions, andequivalents falling within the spirit and scope of the invention.

1-20. (canceled)
 21. A system comprising: a projector that projects a light pattern towards a scene, the projector including: a multimode laser; and a diffractive optical component configured to project the light pattern from the multimode laser and generate one or more triangular grids of a first set of points, associate each point in the first set of points with an intensity value that is within a first intensity range, subdivide the one or more triangular grids of a first set of points into a plurality of second sets of points, and associate each point in the plurality of second sets of points with an intensity value within the second intensity range that is different from the first intensity range.
 22. The system of claim 21, the system further comprising: one or more stereo cameras configured to sense the first set of points and the plurality of second sets of points as left and right stereo camera images.
 23. The system of claim 22, the system further comprising: an image processing component configured to process the stereo camera images into depth maps.
 24. The system of claim 22, wherein the one or more stereo cameras include a pair of stereo cameras and the pair of stereo cameras and the projector are incorporated into a single device.
 25. The system of claim 22, wherein the diffractive optical component is further configured to project the light pattern rotated relative to an orientation of the one or more stereo cameras.
 26. The system of claim 21, wherein the first set of points and the plurality of second sets of points are interleaved via subdivision.
 27. The system of claim 21, wherein one or more of the first set of points and the plurality of second sets of points form approximate regular triangles, based upon repositioning points of substantially regular triangles with additional random repositioning of at least some points thereof.
 28. The system of claim 21, wherein at least one of the points of the first set of points and the plurality of second sets of points is randomly or pseudo-randomly assigned an intensity value within a range of intensities associated with that set of points.
 29. The system of claim 28, wherein the first intensity range and second intensity range overlap and assigning intensity values to the points of the first set of points and the plurality of second sets of points includes applying one or more weighted random techniques to bias assigned intensity values away from values in the overlap of the first intensity range and second intensity range.
 30. The system of claim 21 wherein the projected light pattern comprises infrared light for sensing by infrared stereo cameras, or visible light for sensing by color stereo cameras.
 31. A method comprising: projecting, through a presentation device, a light pattern toward a scene; outputting, through a diffractive component, the light pattern comprising a first set of points corresponding to a first intensity range and a plurality of second sets of points corresponding to a second intensity range, positions of the points in the first set being based on an initial triangular grid layout, and positions of the points in the plurality of second sets of points being based on a subdivision of the initial triangular grid layout; and correlating the first set of points in a left stereo image with the plurality of the second sets of points in a right stereo image.
 32. The method of claim 31 further comprising: sensing, by one or more stereo cameras, the first set of points and the plurality of second sets of points as the left and right stereo camera images.
 33. The method of claim 32 wherein projecting the light pattern comprises projecting the light pattern rotated relative to orientation of the one or more stereo cameras.
 34. The method of claim 32, further comprising: processing, by an image processing component, the stereo camera images into depth maps.
 35. The method of claim 34 wherein the one or more stereo cameras include a pair of synchronized stereo cameras and processing the stereo camera images into depth maps includes extracting matching features from the sensed left and right stereo camera images.
 36. The method of claim 31 further comprising, outputting, through the diffractive component, a third set of points between subsets of points of the plurality of second sets of points corresponding to a third intensity range, and positions of the points in the third set of points being based on subdivision of grid layouts formed by the positions of the plurality of second sets of points.
 37. The method of claim 31 wherein outputting each point in the first set of points with an intensity value that is within a first intensity range comprises randomly or pseudo-randomly selecting an intensity value within the first range for at least some of the points in the first set of points.
 38. The method of claim 31 wherein outputting each point in the plurality of second sets of points with an intensity value that is within a second intensity range comprises randomly or pseudo-randomly selecting an intensity value within the second range for at least some of the points in the plurality of second sets of points.
 39. The method of claim 31 wherein projecting the light pattern includes pulsing the light pattern based on at least one defined parameter.
 40. A method comprising: projecting, through a presentation device, a light pattern toward a scene; outputting, through a diffractive component, the light pattern comprising a first set of points corresponding to a first intensity range and a plurality of second sets of points corresponding to a second intensity range, positions of the points in the first set being based on an initial triangular grid layout, and positions of the points in the plurality of second sets of points being based on a subdivision of the initial triangular grid layout; correlating the first set of points in a left stereo image with the plurality of the second sets of points in a right stereo image; extracting, by an image processing component, matching features from the correlated left and right stereo camera images; and processing, by the image processing component, the stereo camera images into depth maps based on the extracted matching features. 